1. Technical Field
The invention relates generally to product dispensers, and more particularly to a dispenser suitable for an extrudable product such as lipstick, glue, grease, and the like.
2. Background Information
Parent U.S. patent application Ser. Nos. 198,390 and 274,920 describe a two-piece applicator unit about the size of a fountain pen, one piece serving as an applicator and the other as a cover for the applicator tip. The cover contains a supply of an extrudable product and an extrusion mechanism that operates to dispense a desired amount of the product onto the tip. Use proceeds by rotating an extrusion die within the cover in order to operate the extrusion mechanism. That is done by either rotating the applicator relative to the cover or by rotating two sections of the cover relative to each other. Then, the user separates the applicator and cover with a slight tug to expose the applicator tip for product application purposes, finally placing the cover back over the tip when finished for storage.
Such dispensers are very convenient and effective and the parent applications are incorporated by reference for the details provided. But sometimes a user may want to inhibit the passage of air to the supply of extrudable product within the cover to prevent a product from becoming so dry and crusty it impairs extrusion and, in the case of a product such as lipstick, is unacceptably nonuniform for application to the lips. In addition, the user may want to extrude only a desired amount of the product to avoid waste and the possibility that the excess will somehow clog the extrusion mechanism. Thus, it is desirable to have a dispenser with features satisfying those needs.